Inserts, in particular shoe inserts, and in particular heel inserts, are known in various embodiments. Providing a foot with an insert, for example, providing a hind foot with a heel support, serves for compensating differences in the length of legs, for damping one's tread, for absorbing shock peaks, for positively influencing the posture and gait patterns, and the like. Heel supports from silicone-based rubber have been particularly successful because this material cannot be configured so as to be compressible but nevertheless can be configured so as to be resilient/elastic. Silicone-based rubbers in terms of the resilience thereof relating to the respectively set requirements may be readily specified and are also easy to shape.
Conventional visco-elastic inserts, in particular heel inserts, are composed of silicone-based rubber of the same material specification. The distribution of pressure on the foot and in particular on the hind foot may be largely homogenized in this way. However, most often the pressure is higher in the region of the heel spur on the plantar fascia. This may have a negative effect, in particular in the case of malpositioning of the heel or of the heel spur. Accordingly, U.S. Pat. No. 4,928,404 proposed a heel cushion from silicone-based rubber, with a heel bed having a punctiform region which is composed of a silicone-based rubber of softer specification. This soft region is disposed such that it is located below the heel spur, the compressive stress of the hind foot below the heel spur thus being reduced. However, it is disadvantageous in the case of such a punctiform region that a perceptible edge which may cause pain exists between the shore hardness of a spot and of the main body. This is also the case in an embodiment in which the soft region is enlarged, since the respective contours of the sole of the foot cannot be bordered, stabilized, and guided in an anatomically correct manner, potentially enabling the foot to sink into the soft foot bed, which may result in further pain or instability.